Police in Canada said Thursday they may never know why a man went on a stabbing rampage that left 11 people dead and 17 injured last year.

The Royal Canadian Mounted Police released details at a news conference on the Sept. 4 killings in James Smith Cree Nation and the nearby Saskatchewan village of Weldon, but they did not pin down the motive.

Myles Sanderson, the 32-year-old accused in the attacks, died in police custody a few days later.

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Supt. Joshua Graham, the officer in charge of major crimes, said Myles Sanderson and his brother Damien Sanderson went to the James Smith Cree Nation to deal drugs on Sept. 1.

The day before the massacre, Damien Sanderson told people at a nearby bar they had a "mission to do" and that "people would hear all about it in the next few hours." Damien Sanderson, however, was one of the first people killed the morning of the rampage.

Assistant Commissioner Rhonda Blackmore, commanding officer of the Saskatchewan RCMP, said since both Myles and Damian Sanderson are dead "some of the pieces of information may never be known."

"To speak to exactly their mindset and what they were thinking, we can’t necessarily address that," Blackmore said at the news conference.

After the brothers attacked a man in his home with scissors, Myles Sanderson and Damien Sanderson got into a fight in a vehicle. An injured Damien Sanderson fled the vehicle into the trees along the side of the road. His body would be located there the following day.

Myles Sanderson continued to go to different homes in the community, attacking some people and killing others. He threatened other people, saying they were lucky to not be hurt as he stole some of their vehicles.

On Sept. 9, after a three-day manhunt and hundreds of reported sightings, police arrested Myles Sanderson on a highway near Rosthern, Saskatchewan. He went into medical distress soon after he was placed in custody and died.

Blackmore was asked why the RCMP were not able to apprehend Myles Sanderson sooner.

"His attacks were unpredictable," she said. "As fast as information was coming in about a vehicle he was in, he was abandoning that vehicle, moving on foot and then stealing other vehicles.

"It was a very rapidly unfolding, very dynamic and chaotic situation."

Police say that after nearly eight months, the investigation into the stabbing rampage is still not complete.

Blackmore said RCMP examined 42 different crime scenes, including buildings and vehicles. They also seized about 700 exhibits and spoke with more than 250 witnesses.

A handful of people from the community attended the presentation in Melfort, but victims and their families received the update on Wednesday.

Darryl Burns, whose sister Lydia Gloria Burns died in the stabbings, said it brought some closure.

"The way the morning went there was so much confusion, there was so much turmoil," Burns said. "Looking back on it, you couldn’t really tell where he was going to go or what he was going to do."

He said there was a lot of emotion and "lot of the sorrow and sadness" hearing the timeline.

Police said the update won’t affect two coroner’s inquests set for early next year.

One of the inquests is to focus on the killings, while the other is to look at the suspect. Police have said Sanderson went into medical distress shortly after he was arrested near the Saskatchewan town of Rosthern.

An independent investigation is also being conducted by Saskatoon police and the Saskatchewan Serious Incident Response Team.

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Police had previously released some details about the deadly rampage on the First Nation about 105 miles northeast of Saskatoon.

Four dangerous persons alerts were released before 10 a.m. saying there had been multiple victims and giving descriptions of the suspects and the vehicle in which they were believed to be travelling.

Later that day, police announced multiple people had died or were injured in the attacks, which took place across 13 locations.

The province was on edge and police remained on the lookout for days. Blackmore said police received tips from across Canada with people certain they had seen Myles Sanderson.

"It takes time as we assess the information as it comes in to determine which is credible information or not as it unfolds," she said.

By Sept. 7, there was a break in the case. A 911 call came from the town of Wakaw, about 68 miles southwest of the First Nation, about a stolen white truck. Police vehicles sped down rural roads in the area and a helicopter hovered overhead.

The suspect vehicle hit a ditch and drove into trees along the highway near Rosthern. Myles Sanderson was taken into police custody but went into medical distress shortly after and died.